Look, If you're going to combine melee and ranged weapons into one weapon you're much better off making a gun-axe:

And if that's not practical enough for you just attach a bayonet to your rifle and you have a gun-spear.

heavy and impractical.

guns with axe bayonets, on the other hand, are much more practical because you can actually use the bayonet as a bipod in wooded environments